/* ITU-T G.729 Software Package Release 2 (November 2006) */
/* Version 1.2    Last modified: May 1998 */
/* from dec_gain.c G.729 Version 3.3            */

#include <stdlib.h>
#include <stdio.h>

#include "typedef.h"
#include "basic_op.h"
#include "ld8k.h"
#include "tab_ld8k.h"


/*---------------------------------------------------------------------------*
 * Function  Dec_gain                                                        *
 * ~~~~~~~~~~~~~~~~~~                                                        *
 * Decode the pitch and codebook gains                                       *
 *                                                                           *
 *---------------------------------------------------------------------------*
 * input arguments:                                                          *
 *                                                                           *
 *   index      :Quantization index                                          *
 *   code[]     :Innovative code vector                                      *
 *   L_subfr    :Subframe size                                               *
 *   bfi        :Bad frame indicator                                         *
 *                                                                           *
 * output arguments:                                                         *
 *                                                                           *
 *   gain_pit   :Quantized pitch gain                                        *
 *   gain_cod   :Quantized codebook gain                                     *
 *                                                                           *
 *---------------------------------------------------------------------------*/
void Dec_gaine(
   Word16 index,        /* (i)     :Index of quantization.         */
   Word16 code[],       /* (i) Q13 :Innovative vector.             */
   Word16 L_subfr,      /* (i)     :Subframe length.               */
   Word16 bfi,          /* (i)     :Bad frame indicator            */
   Word16 *gain_pit,    /* (o) Q14 :Pitch gain.                    */
   Word16 *gain_cod,     /* (o) Q1  :Code gain.                     */
   Word16 rate,        /* (i)   : number of bits per frame             */
   Word16 gain_pit_mem,
   Word16 gain_cod_mem,
   Word16  *c_muting,
   int      count_bfi,
   int      stationnary

)
{
   Word16  index1, index2, tmp;
   Word16  gcode0, exp_gcode0;
   Word32  L_gbk12, L_acc, L_accb;
   void    Gain_predict( Word16 past_qua_en[], Word16 code[], Word16 L_subfr,
                        Word16 *gcode0, Word16 *exp_gcode0 );
   void    Gain_update( Word16 past_qua_en[], Word32 L_gbk12 );
   void    Gain_update_erasure( Word16 past_qua_en[] );

        /* Gain predictor, Past quantized energies = -14.0 in Q10 */

   static Word16 past_qua_en[4] = { -14336, -14336, -14336, -14336 };



   /*-------------- Case of erasure. ---------------*/

    if(bfi != 0) {
        if(rate == 1) {
            if (count_bfi < 2) {
                if (stationnary) *gain_pit = 16384;
                else *gain_pit = 15564;
                *gain_cod = gain_cod_mem;
            }
            else {
                *gain_pit = mult(gain_pit_mem, *c_muting);
                *gain_cod = mult(gain_cod_mem, *c_muting);
                if (stationnary) {
                    if (count_bfi > 10) *c_muting = mult( *c_muting, 32604);
                }
                else *c_muting = mult( *c_muting, 32112);

            }
        }
        else {
            *gain_pit = mult( gain_pit_mem, 29491 );      /* *0.9 in Q15 */
            if (sub( *gain_pit, 29491) > 0) *gain_pit = 29491;
            *gain_cod = mult( gain_cod_mem, 32111 );      /* *0.98 in Q15 */
        }
        /*----------------------------------------------*
        * update table of past quantized energies      *
        *                              (frame erasure) *
        *----------------------------------------------*/
        Gain_update_erasure(past_qua_en);

        return;
    }


   /*-------------- Decode pitch gain ---------------*/

   index1 = imap1[ shr(index,NCODE2_B) ] ;
   index2 = imap2[ index & (NCODE2-1) ] ;
   *gain_pit = add( gbk1[index1][0], gbk2[index2][0] );

   /*-------------- Decode codebook gain ---------------*/

  /*---------------------------------------------------*
   *-  energy due to innovation                       -*
   *-  predicted energy                               -*
   *-  predicted codebook gain => gcode0[exp_gcode0]  -*
   *---------------------------------------------------*/

   Gain_predict( past_qua_en, code, L_subfr, &gcode0, &exp_gcode0 );

  /*-----------------------------------------------------------------*
   * *gain_code = (gbk1[indice1][1]+gbk2[indice2][1]) * gcode0;      *
   *-----------------------------------------------------------------*/

   L_acc = L_deposit_l( gbk1[index1][1] );
   L_accb = L_deposit_l( gbk2[index2][1] );
   L_gbk12 = L_add( L_acc, L_accb );                       /* Q13 */
   tmp = extract_l( L_shr( L_gbk12,1 ) );                  /* Q12 */
   L_acc = L_mult(tmp, gcode0);             /* Q[exp_gcode0+12+1] */

   L_acc = L_shl(L_acc, add( negate(exp_gcode0),(-12-1+1+16) ));
   *gain_cod = extract_h( L_acc );                          /* Q1 */

  /*----------------------------------------------*
   * update table of past quantized energies      *
   *----------------------------------------------*/
    Gain_update( past_qua_en, L_gbk12 );

   return;

}
